Gamma-ray Burst 221017A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN Notice

TITLE:           GCN/MAXI NOTICE
NOTICE_DATE:     Mon 17 Oct 22 05:43:35 UT
NOTICE_TYPE:     MAXI Unknown Source Position
EVENT_ID_NUM:      9869163312
EVENT_RA:        116.75d {+07h 47m 01s} (J2000),
                 117.14d {+07h 48m 33s} (current),
                 115.91d {+07h 43m 38s} (1950)
EVENT_DEC:       +39.29d {+39d 17' 20"} (J2000),
                 +39.23d {+39d 13' 53"} (current),
                 +39.41d {+39d 24' 45"} (1950)
EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
EVENT_FLUX:      0.0 +- 0.0 [mCrab]
EVENT_DATE:      19869 TJD;   290 DOY;   22/10/17
EVENT_TIME:      20380.00 SOD {05:39:40.00} UT
EVENT_TSCALE:    30s
EVENT_EBAND:     Low, 2-4 keV
SUN_POSTN:       202.07d {+13h 28m 16s}   -9.25d {-09d 14' 59"}
SUN_DIST:         91.95 [deg]
MOON_POSTN:      110.91d {+07h 23m 38s}  +26.89d {+26d 53' 39"}
MOON_DIST:        13.39 [deg]
MOON_ILLUM:      55 [%]
GAL_COORDS:      180.42, 27.01 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      111.47, 17.82 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.

GCN Notice

TITLE:           GCN/MAXI NOTICE
NOTICE_DATE:     Mon 17 Oct 22 05:59:55 UT
NOTICE_TYPE:     MAXI Unknown Source Position
EVENT_ID_NUM:      9869163312
EVENT_RA:        116.86d {+07h 47m 26s} (J2000),
                 117.24d {+07h 48m 58s} (current),
                 116.01d {+07h 44m 03s} (1950)
EVENT_DEC:       +39.41d {+39d 24' 32"} (J2000),
                 +39.35d {+39d 21' 04"} (current),
                 +39.53d {+39d 31' 58"} (1950)
EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
EVENT_FLUX:      0.0 +- 0.0 [mCrab]
EVENT_DATE:      19869 TJD;   290 DOY;   22/10/17
EVENT_TIME:      20380.00 SOD {05:39:40.00} UT
EVENT_TSCALE:    30s
EVENT_EBAND:     Low, 2-4 keV
SUN_POSTN:       202.08d {+13h 28m 19s}   -9.25d {-09d 15' 14"}
SUN_DIST:         91.91 [deg]
MOON_POSTN:      111.06d {+07h 24m 14s}  +26.88d {+26d 52' 48"}
MOON_DIST:        13.50 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:      180.31, 27.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      111.53, 17.96 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.

GCN Circular #32777
S. Nawa(Chuo U.), M. Serino(AGU), H. Negoro, M. Nakajima, K. Kobayashi, M. Tanaka, Y. Soejima (Nihon U.), T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, H. Hiramatsu, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, J. Kohara, S. Urabe, N. Nemoto (Chuo U.), M. Shidatsu, M. Iwasaki (Ehime U.), N. Kawai, M. Niwano, R. Hosokawa, Y. Imai, N. Ito, Y. Takamatsu (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, T. Kurihara (JAXA), Y. Ueda, S. Ogawa, K. Setoguchi, T. Yoshitake, K. Inaba (Kyoto U.), M. Yamauchi, T. Sato, R. Hatsuda, R. Fukuoka, Y. Hagiwara, Y. Umeki (Miyazaki U.), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) report on behalf of the MAXI team:
The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 2022-10-17T05:39:31 UT. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (116.859 deg, 39.409 deg) = (07 47 26, +39 24 32) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.45 deg and 0.4 deg, respectively. The roll angle of long axis from the north direction is 83.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 109 +- 30 mCrab (4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners:
```
(R.A., Dec) = (115.407, 38.740) deg = (07 41 37, +38 44 24) (J2000)
(R.A., Dec) = (116.206, 38.225) deg = (07 44 49, +38 13 30) (J2000)
(R.A., Dec) = (118.217, 40.060) deg = (07 52 52, +40 03 36) (J2000)
(R.A., Dec) = (117.412, 40.589) deg = (07 49 38, +40 35 20) (J2000)
```
There was no significant excess flux in the previous transit at 10/17 04:06 UT with an upper limit of 20 mCrab for each.
GCN Circular #32779
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University)
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the MAXI GRB221017.24 (trigger No 869163312,07h 47m 00.96s , +39d 17m 20.4s, R=1) errorbox 11012 sec after notice time and 11250 sec after trigger time at 2022-10-17 08:47:10 UT, with upper limit up to 17.2 mag. Observations started at twilight. The observations began at zenith distance = 75 deg. The sun altitude is -14.6 deg.
The galactic latitude b = 28 deg., longitude l = 181 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2124323
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   11341 | 2022-10-17 08:47:10 |         MASTER-OAFA | (07h 45m 27.51s , +39d 22m 35.4s) |   C |   180 | 17.2 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #32787
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars-Odyssey team,
A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko, and T. Cline on behalf of the Konus-Wind team,
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr, and A.S. Gardner on on behalf of the GRS-Odyssey GRB team, report:
The long-duration GRB 221017A (MAXI/GSC detection: Nawa et al., GCN 32777) has been detected by MAXI (GSC), INTEGRAL (SPI-ACS), Konus-Wind, and Mars-Odyssey (HEND), so far, at about 19789 s UT (05:29:49).
We have triangulated it to a preliminary, 3 sigma error box whose coordinates are:
```
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  116.901 (07h 47m 36s) +39.742 (+39d 44' 32")
 Corners:
  116.215 (07h 44m 52s) +41.438 (+41d 26' 15")
  117.708 (07h 50m 50s) +38.402 (+38d 24' 08")
  117.493 (07h 49m 58s) +37.908 (+37d 54' 28")
  116.024 (07h 44m 06s) +40.992 (+40d 59' 30")
 ---------------------------------------------
```
The error box area is 1.01 sq. deg, and its maximum dimension is 3.7 deg (the minimum one is 19 arcmin). The Sun distance was 91 deg.
This box may be improved.
The IPN localization is consistent with, but reduces the area of, the MAXI/GSC localization (GCN 32777).
A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB221017_T19789/IPN
The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
GCN Circular #32790
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the MAXI GRB 221017A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021529
Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the MAXI event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular #32807
J.P. Osborne (U. Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), J. D. Gropp (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the MAXI-detected burst GRB 221017A (Nawa et al. GCN Circ. 32777), collecting 1.9 ks of Photon Counting (PC) mode data between T0+196.7 ks and T0+225.8 ks.
Two uncatalogued sources are detected:
- Source 1
```
RA (J2000.0): 116.8816 = 07:47:31.58
Dec (J2000.0): 39.3449 = +39:20:41.5
Error: 10.7" (radius, 90% confidence)
Avg. XRT count-rate: 5.4(+2.6,-2.0)x10^(-3) cts/s
```
- Source 2
```
RA (J2000.0): 116.9220 = 07:47:41.27
Dec (J2000.0): 39.2614 = +39:15:41.2
Error: 10.0" (radius, 90% confidence)
Avg. XRT count-rate: 3.3(+2.1,-1.5)x10^(-3) cts/s
```
Both sources lie inside the overlap of the MAXI localization error box (Nawa et al. GCN Circ. 32777) and the IPN triangulation region (Kozyrev et al. GCN Circ. 32787).
The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021529.
This circular is an official product of the Swift-XRT team.
GCN Circular #32813
M. L. Cherry (LSU), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
The long GRB 221017A (MAXI/GSC detection: Nawa et al., GCN Circ. 32777; IPN triangulation: Kozyrev et al., GCN Circ 32787) was detected in the ground analysis of the CALET Gamma-ray Burst Monitor (CGBM) data around 05:29:49 UTC on October 17, 2022 (referenced to GCN Circ 32787). The burst signal was seen by all CGBM detectors.
The burst light curve shows a multi-peaked structure that starts at T-20.5 sec, peaks at T+176.6 sec and ends at T+670.4 sec. The T90 and T50 durations measured by the SGM data are 191.9 +/- 44.4 sec and 52.7 +/- 0.5 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1350019714/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.
GCN Circular #32872
A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long-duration GRB 221017A (MAXI/GSC detection: Nawa et al., GCN 32777; IPN triangulation: Kozyrev et al., GCN 32787; CALET/CGBM detection: Cherry et al., GCN 32813) triggered Konus-Wind at T0=19789.594 s UT (05:29:49.594).
The burst light curve shows a multipeaked structure which starts at ~T0-19.1 s and has a total duration of ~332 s. The emission is seen up to ~6 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB221017_T19789/
As observed by Konus-Wind, the burst had a fluence of 3.90(-0.32,+0.32)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+175.872 s, of 9.62(-1.55,+1.56)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+312.320 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.99(-0.06,+0.07), the high energy photon index beta = -2.75(-0.46,+0.23), the peak energy Ep = 237(-15,+16) keV (chi2 = 119/98 dof).
The spectrum near the maximum count rate (measured from T0+151.552 to T0+182.016 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.92(-0.04,+0.04), the high energy photon index beta = -2.98(-0.35,+0.22), the peak energy Ep = 288(-13,+13) keV (chi2 = 137/98 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.

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Jochen Greiner, last update: 28-Oct-2022 [Disclaimer]